Care of the Patient with Retinal Detachment And Related Peripheral Vitreoretinal Disease docx

Care of the Patient with
Retinal Detachment
And
Related Peripheral
Vitreoretinal
Disease
OPTOMETRIC CLINICAL
PRACTICE GUIDELINE


OPTOMETRY:
THE PRIMARY EYE CARE PROFESSION

Doctors of optometry are independent primary health care providers who
examine, diagnose, treat, and manage diseases and disorders of the visual
system, the eye, and associated structures as well as diagnose related
systemic conditions.

Optometrists provide more than two-thirds of the primary eye care
services in the United States. They are more widely distributed
geographically than other eye care providers and are readily accessible
for the delivery of eye and vision care services. There are approximately
32,000 full-time equivalent doctors of optometry currently in practice in
the United States. Optometrists practice in more than 7,000 communities
across the United States, serving as the sole primary eye care provider in
more than 4,300 communities.

The mission of the profession of optometry is to fulfill the vision and eye
care needs of the public through clinical care, research, and education, all
of which enhance the quality of life.


OPTOMETRIC CLINICAL PRACTICE GUIDELINE
CARE OF THE PATIENT WITH RETINAL DETACHMENT
AND RELATED PERIPHERAL VITREORETINAL DISEASE

Reference Guide for Clinicians


Prepared by the American Optometric Association Consensus Panel on
Care of the Patient with Retinal Detachment and Related Peripheral
Vitreoretinal Disease:

William L. Jones, O.D., Principal Author
Anthony A. Cavallerano, O.D.
Kirk M. Morgan, M.D.
Leo P. Semes, O.D.
Jerome F. Sherman, O.D.
Robert S. Vandervort, O.D.
Robert P. Wooldridge, O.D.


Reviewed by the AOA Clinical Guidelines Coordinating Committee:

John F. Amos, O.D., M.S., Chair
Barry Barresi, O.D., Ph.D.
Kerry L. Beebe, O.D.

Jerry Cavallerano, O.D., Ph.D.
John Lahr, O.D.
David Mills, O.D.


Approved by the AOA Board of Trustees April 27, 1995(1
st
ed).
Reviewed April 1998, Revised June 1999, Reviewed 2004
© AMERICAN OPTOMETRIC ASSOCIATION 1995
243 N. Lindbergh Blvd., St. Louis, MO 63141-7881


Printed in U.S.A.


NOTE: Clinicians should not rely on the Clinical
Guideline alone for patient care and management.
Refer to the listed references and other sources
for a more detailed analysis and discussion of
research and patient care information. The
information in the Guideline is current as of the
date of publication. It will be reviewed periodically
and revised as needed.

Retinal Detachment iii

TABLE OF CONTENTS
INTRODUCTION 1
I. STATEMENT OF THE PROBLEM 3
A. Description and Classification of Retinal Detachment and Related
Peripheral Vitreoretinal Disease 3
1. Retinal Detachment 3
a. Rhegmatogenous Retinal Detachment 4
b. Nonrhegmatogenous Retinal Detachment 4
2. Retinal Breaks 4
a. Atrophic Retinal Holes 4
b. Operculated Retinal Tears 5
c. Horseshoe and Linear Retinal Tears 5
d. Retinal Dialysis 6
3. Related Peripheral Vitreoretinal Disease 6
a. Retinal Tufts 6
b. Lattice Retinal Degeneration 7
c. Snail-Track Degeneration 8
d. Retinoschisis 9
e. White-Without-Pressure 10
f. Meridional Folds and Complexes 10
g. Peripheral Pigmentary Degeneration and Pigment
Clumping 11
h. Peripheral Retinal Hemorrhage 12
i. Pars Planitis 12
j. Chorioretinal Scar 13
k. Posterior Vitreous Detachment 14

B. Epidemiology of Retinal Detachment and Related Peripheral
Vitreoretinal Disease 15
1. Retinal Detachment 15
a. Prevalence and Incidence 15
b. Risk Factors 15
2. Retinal Breaks 18
a. Prevalence and Incidence 18
b. Risk Factors 19
3. Related Peripheral Vitreoretinal Disease 19
a. Prevalence and Incidence 19
b. Risk Factors 21
C. Clinical Background of Retinal Breaks and Detachment 23
1. Retinal Breaks 23
a. Natural History 23
b. Common Signs, Symptoms, and Complications 24
iv Retinal Detachment


2. Retinal Detachment 25
a. Natural History 25
b. Common Signs, Symptoms, and Complications 26
3. Early Detection and Prevention 27

II. CARE PROCESS 29
A. Diagnosis of Retinal Detachment and Related Peripheral
Vitreoretinal Disease 29
1. Patient History 29
2. Ocular Examination 29
3. Supplemental Testing 30
B. Management of Retinal Breaks and Detachment 31

1. Management Strategy for Retinal Breaks 32
2. Management Strategy for Retinal Detachment 34
3. Patient Education 36
4. Prognosis and Followup 36
a. Retinal Breaks 36
b. Retinal Detachment 37
5. Management of Patients with Severe, Irreversible Vision
Loss 38

CONCLUSION 41

III. REFERENCES 42

IV. APPENDIX 63
Figure 1: Optometric Management of the Patient with Peripheral
Vitreoretinal Disease: A Brief Flowchart 63
Figure 2: Optometric Management of the Patient with Retinal
Detachment: A Brief Flowchart 64
Figure 3: Frequency and Composition of Evaluation and Management
Visits for Retinal Detachment and Related Peripheral
Vitreoretinal Disease 65
Figure 4: ICD-9-CM Classification of Retinal Detachment and Related
Peripheral Vitreoretinal Disease 67
Abbreviations of Commonly Used Terms 72
Glossary 73

Introduction 1

INTRODUCTION

Optometrists, through their clinical education, training, experience, and
broad geographic distribution, have the means to provide effective
primary eye and vision care services for a significant portion of the
American public and are often the first health care practitioners to
diagnose patients with diseases of the retina.

This Optometric Clinical Practice Guideline for Care of the Patient with
Retinal Detachment and Related Peripheral Vitreoretinal Disease
describes appropriate examination and treatment procedures to reduce
the risk of potential loss of vision from peripheral retinal problems. It
contains recommendations for timely diagnosis, treatment, and, when
necessary, referral for consultation with or treatment by another health
care provider. The Guideline will assist optometrists in achieving the
following goals:

• Diagnose significant or frequently encountered peripheral
vitreoretinal diseases and related congenital ocular abnormalities
• Improve the quality of care rendered to patients with retinal
diseases and related congenital ocular abnormalities
• Identify patients at risk of developing retinal breaks or detachment
• Minimize the ocular morbidity and severe vision loss related to
retinal disease through diligent monitoring and timely consultation
or referral
• Monitor the gains obtained through treatment
• Inform and educate patients and other health care practitioners
about the complications and prevention of retinal disease and the
availability of treatment.

Statement of the Problem 3

I. STATEMENT OF THE PROBLEM

A retinal detachment can have devastating visual consequences. The
patient with retinal detachment may lose a portion or all of the vision in
the involved eye, resulting in a significant reduction in visual
performance and an inability to function at his or her occupation and
other activities of daily living. Retinal detachment often requires
surgical repair, which has inherent risks.

Detection of a retinal detachment requires a thorough evaluation,
incorporating a detailed patient history and a stereoscopic examination of
the entire retina through a dilated pupil. The evaluation of conditions
predisposing to retinal detachment requires knowledge of peripheral
vitreoretinal diseases that may lead to detachment.

A. Description and Classification of Retinal Detachment and
Related Peripheral Vitreoretinal Disease

This Guideline presents the most common peripheral retinal diseases
associated with retinal detachment (See Appendix Figure 4 for the ICD-
9-CM classification of retinal detachment and related peripheral
vitreoretinal disease).

1. Retinal Detachment

A retinal detachment is a separation of the sensory retina from the
underlying retinal pigment epithelium (RPE). There are numerous

variations in the basic pathogenesis of a retinal detachment. They
include developmental factors (e.g., myopia and Marfan syndrome) that
affect the overall size and shape of the globe,
1
vitreoretinal disorders
(e.g., coloboma and retinal dysplasia), metabolic disease (e.g., diabetic
retinopathy), vascular disease (e.g., sickle cell disease), trauma,
inflammation, degenerative conditions, and neoplasms. Retinal
detachments can be classified as rhegmatogenous or
nonrhegmatogenous.

4 Retinal Detachment

a. Rhegmatogenous Retinal Detachment

The most common type of retinal detachment, rhegmatogenous, results
from a break in the sensory retina. The break is most often caused by
vitreous traction on the surface of the retina. This traction physically
pulls a small section of the sensory retina away from the pigment
epithelium, resulting in what is called a "retinal tear." Traction at the site
of a tear can initiate retinal detachment surrounding the tear by pulling
on the surface of the adjacent retina. The break in the retina may also
allow fluid from the vitreous cavity to percolate into the potential
subretinal space. Thus, a rhegmatogenous retinal detachment caused by
a retinal tear is the result of both vitreous traction and fluid ingress
between the sensory retina and the pigment epithelium.

b. Nonrhegmatogenous Retinal Detachment

The second type of retinal detachment, nonrhegmatogenous, usually

results from the accumulation of exudate or transudate in the potential
subretinal space, rather than from a retinal break. Sometimes a
nonrhegmatogenous retinal detachment is caused by sheer traction,
without the production of a retinal tear. Other etiologies of this type of
detachment include chorioretinitis, metastatic choroidal tumor, choroidal
effusion, retinal angioma, Harada's disease, pars planitis, sympathetic
ophthalmia, eclampsia, and trauma.

2. Retinal Breaks

Any discontinuity of the neurosensory retina is called a retinal break.
When the break results from vitreous traction, it is referred to as a "tear."
When the break results from a focal loss of retinal tissue, it is atrophic
and referred to as a retinal "hole." Although there are specific
distinctions between holes and tears, these terms are often used
interchangeably.
2


a. Atrophic Retinal Holes

A retinal break that is not caused by vitreous traction but is most likely
produced by an atrophic process in which vascular insufficiency of the
Statement of the Problem 5

underlying choriocapillaris impairs retinal circulation is an atrophic
retinal hole. Thinning and degeneration of blood vessels eventually lead
to the clinical appearance of small, round defects in an area of thin,
partially opaque sensory retina. The sizes of these holes vary from
pinpoint to 1.5 disc diameters (DD).

3
In the attached retina, the holes are
more red than adjacent retinal tissue. Due to the obstructed view of the
underlying choriocapillaris in a detached retina, the holes appear pinkish,
grayish, or clear depending on the view of the underlying choroid.
Although they may be found in any region of the fundus, most retinal
holes occur in the temporal half of the retina and are usually confined to
the region between the equator and the ora serrata.

b. Operculated Retinal Tears

When there is significant vitreous traction in a small, discrete area of the
retina, the increased vitreoretinal adhesion can result in an operculated
retinal tear. The traction pulls a small plug of sensory retina (an
operculum) out of the surrounding retina. The operculum, which can be
seen as a whitish, disc-shaped floater over the retinal break, moves upon
eye movements because it is attached to the detached vitreous cortex.
Because it has been separated from its blood supply, the operculum
becomes smaller than the break due to contraction secondary to
degeneration. Operculated tears in the attached sensory retina are
usually round and appear more red than the surrounding retina. They are
generally located between the ora serrata and the equator, more
frequently in the temporal half of the retina; however, they may occur in
any region of the retina.

c. Horseshoe and Linear Retinal Tears

Significant localized vitreous traction can cause horseshoe (flap) or
linear retinal tears. Horseshoe tears, which are much more common than
linear tears, are the result of vitreous traction pulling a horseshoe-shaped

thin curvilinear flap of sensory retina into the vitreous cavity. Away
from its blood supply, this flap which is attached at the anterior margin
of the tear contracts and degenerates to become smaller than the break.
A tear in the attached sensory retina appears more red than the
surrounding retina, and the apex of the tear almost always points to the
6 Retinal Detachment

posterior pole. Such tears can exist in any region of the peripheral retina;
however, they are most often found near the posterior margin of the
vitreous base in areas of lattice degeneration, pigment clumps, or retinal
tufts.

d. Retinal Dialysis

A retinal tear that occurs at the ora serrata, concentric with the ora, is
called a retinal dialysis. Most of these tears are less than 90 degrees, and
they are rarely bilateral. The underlying pigment epithelium becomes
more visible in the area of the tear due to the loss of the overlying retina.
If the edge of the dialysis remains close to the RPE, then the tear may not
be discovered unless scleral depression is performed. As the vitreous
contracts, the tear becomes more elevated in conjunction with an
increase in the associated retinal detachment.

There are two types of retinal dialysis: congenital and post-traumatic.
The congenital form, which is found in young people, is spontaneous and
is associated with an asymptomatic, slowly progressive retinal
detachment. Congenital dialyses usually occur in the inferior temporal
region of the retina, and their bilateralism is in marked contrast to those
of post-traumatic etiology.
4

Post-traumatic dialyses, which are more
common, usually occur in the superior nasal region of the retina;
however, a blow to the eye at the temporal limbus may result in an
inferior, temporal dialysis.
5
The trauma responsible for the tear may
have occurred in the distant past.

3. Related Peripheral Vitreoretinal Disease

a. Retinal Tufts

Retinal tufts are small areas of gliotic degeneration of the retina
associated with vitreous traction. They may be classified as noncystic,
cystic, or zonular traction tufts. Noncystic tufts are short (<0.1 mm),
thin, internal projections that are often found in clusters. They are almost
always located within the vitreous base but may be found elsewhere in
the pre-equatorial retina. Larger than noncystic tufts (>0.1 mm), cystic
tufts are nodular projections of retinal tissue that occur either within or
Statement of the Problem 7

posterior to the vitreous base. About 78 percent occur in the equatorial
zone.
6
They can be found in any quadrant of the retina, are often
unilateral, and usually occur singly. Zonular traction tufts are gliotic
tufts that are pulled in an anterior direction by a zonular fiber and,
therefore, appear as thin strands, stretched over the ora serrata. They are
usually solitary lesions and are often within the vitreous base. Zonular
traction tufts, which are most commonly located in the nasal half of the

retina, are attached to the retina less than 0.5 mm posterior to the ora
serrata; only rarely are they attached posterior to the vitreous base.
7-9


Retinal tufts are generally stable in size over time, but they may have
slight changes in shape due to continuous vitreous traction. Because of
the traction exerted by the overlying vitreous, cystic and zonular traction
tufts can be associated with a retinal tear and subsequent retinal
detachment. Cystic tufts account for the development of as many as 10
percent of rhegmatogenous retinal detachments.
8,10-13
Atrophic retinal
holes from retinal thinning adjacent to cystic tufts rarely result in retinal
detachment and carry a risk factor of less than 0.3 percent.
11
Zonular
traction tufts may have associated retinal holes at the posterior margin,
but these tufts only account for 0.11 percent of retinal tears in autopsied
eyes.
6
Because zonular traction tufts are often intrabasal (i.e., occur
within the area of the vitreous base), they are rarely associated with
retinal detachment.

b. Lattice Retinal Degeneration

Lattice retinal degeneration is a vitreoretinal degeneration that manifests
changes in both the retina and the overlying vitreous. The involved
retina thins and becomes fibrotic, while the vitreous forms a pocket of

liquefaction (lacuna) immediately above the affected area of the retina.
In many cases, the degenerative insult to the retina causes the tissue to
become hyperpigmented, and in about 12-43 percent of cases, it also
causes vessels that cross the lesion to develop white sclerotic walls.
14

Lattice retinal degeneration usually occurs in the far periphery of the
retina, and only occasionally in the equatorial region. It is more common
adjacent to the superior and inferior meridians.
6
The lesions range from
1 to 4 DD in length and from 0.5 to 1.75 DD in width. In 48.1 percent of
cases, lattice degeneration is bilateral and fairly symmetrical.
15
The
8 Retinal Detachment

number of lesions in one eye can vary from 1 to 19, averaging 2.4 per
eye.
16


Lattice retinal degeneration and retinal detachment have a significant
association. Lattice degeneration has been found in 20-35 percent of
patients undergoing surgery for rhegmatogenous detachments.
17-22

However, this association does not mean that patients with this condition
are likely to develop retinal detachment; in fact, detachment is reported
in only 0.3-0.5 percent of patients with lattice degeneration.

14,23


Progressive thinning of the retina due to the overlying liquefied vitreous
and vitreous traction at the edges of the lattice lesions may lead to retinal
break formation in up to 25 percent of eyes with lattice degeneration.
19

Thinning of the retina can result in the formation of atrophic holes in as
many as 18.2-29.2 percent of cases.
14,19,24,25
In one study, 75 percent of
all atrophic holes occurred within the area of lattice degeneration.
26

However, the frequency of retinal detachment caused by atrophic holes
in lattice degeneration is relatively low and has been reported to be 2.8
percent,
27
13.9 percent,
28
and 9.5 percent.
29
One study found that over a
3 to 9 year period, the incidence of atrophic holes in lattice that
progressed to retinal detachment was zero.
30


In a later study, the same author found that of 276 consecutive untreated

patients (average followup 11 years) fewer than 1 percent developed
detachment.
31
However, there have been two reports of atrophic holes
that were responsible for approximately 30-44 percent of retinal
detachments associated with lattice degeneration.
23,29
Thus considerable
controversy exists concerning risk for retinal detachments as sequelae of
atrophic holes in lattice degeneration; however, in the absence of
concomitant risk factors, most of these lesions need only be followed and
the patient educated about possible complications.

c. Snail-Track Degeneration

A vitreoretinal degeneration similar to lattice retinal degeneration, snail-
track degeneration also results in retinal thinning as a result of a pocket
of vitreous liquefaction (lacuna) just above the lesion. It appears as a
glistening white (frost-like) area of the retina, often with numerous
Statement of the Problem 9

yellow-white flecks through the lesion. Snail-track lesions are similar in
size to those of lattice degeneration, and they occur in the same region of
the retina, usually between the equator and the ora serrata.
Approximately 80 percent of them occur in a zone between the ora
serrata and 2 DD anterior to the equator.
32
Most frequently occurring in
the temporal half of the retina, snail-track degeneration has the same
propensity to form retinal atrophic holes, tears, and detachments as

lattice degeneration. The holes in snail-track degeneration tend to be
larger, however.

d. Retinoschisis

Retinoschisis is a splitting of the sensory retina into two layers and the
filling of the cavity formed by this process with a rather thick fluid. The
lesion is elevated, bullous, and "blister"-like. Its inner layer is smooth
and taut; it does not undulate with eye movement. This inner layer may
contain white sclerotic blood vessels and perhaps snowflake-like
deposits. Whereas a fresh retinal detachment demonstrates a relative
scotoma on visual field testing, a retinoschisis lesion is characteristically
an absolute sharp-margined scotoma.

Retinoschisis most frequently occurs in the temporal region of the retina,
about 70 percent in the inferior and about 25 percent in the superior
temporal quadrants.
33
Peripheral cystoid degeneration always occurs
anterior to the retinoschisis, and coalescence of the cystoid cavities is
believed to be partially responsible for the formation of the lesions.
34

Peripheral vitreous traction often plays a major role in retinoschisis
formation. Although this condition is usually stable over time, in some
cases, retinoschisis may progress slowly toward the posterior pole.

More than 25 percent of eyes with acquired retinoschisis demonstrate at
least one retinal break in one layer of the split retina.
35

Routine autopsy
examination of eyes with no history of ocular disease revealed that
nearly 1 percent had retinoschisis with outer layer breaks.
34
Holes can
develop in either or both of the layers of the retinoschisis. A hole in the
inner layer alone does not lead to any complications because it only
allows fluid from the vitreous cavity to enter the retinoschisis cavity,
which does not increase the size of the lesion. Usually, a hole in the
10 Retinal Detachment

outer layer is of little consequence because it produces only a localized
retinal detachment around the hole. Two large studies showed that
retinoschisis with outer layer breaks rarely progressed to retinal
detachment.
36,37
Another study found a low prevalence (<16%) of retinal
detachment in such cases.
38


The greatest risk factor for retinal detachment in retinoschisis is the
presence of holes in both the inner and outer layers of the retina. Holes
in both layers can allow a larger amount of fluid from the vitreous cavity
to migrate into the potential subretinal space, therefore, resulting in
retinal detachment. However, recent long-term observation studies on
the likelihood of producing a retinal detachment have been less than
conclusive.
37

e. White-Without-Pressure

Retinal white-without-pressure (WWOP) is an optical phenomenon in
which vitreous traction on the underlying retinal surface changes the
retinal coloration from its usual orange-red appearance to a translucent
white or gray-white. These color changes may occur in a small isolated
area or as broad areas in the peripheral retina. Although WWOP may
occur at any retinal location, it occurs more frequently in the superior or
temporal areas. It rarely occurs near the posterior pole; however, it is not
uncommon to find WWOP at the posterior edge of lattice retinal
degeneration. WWOP is generally stable between examinations, but its
configuration sometimes changes.
39


f. Meridional Folds and Complexes

Spindle-shaped rolls of peripheral retinal tissue called meridional folds
are caused by vitreous traction. Although they are usually aligned with a
dentate process, meridional folds can be found at the end of an ora bay.
A meridional complex is a meridional fold associated with an enlarged
dentate process and a ciliary process.

Meridional folds can extend posteriorly for 0.6-6.0 mm and are usually
found in the superior nasal quadrant of the retina.
6
It is unusual to find
peripheral cystoid degeneration adjacent to the folds. Meridional
Statement of the Problem 11

complexes are also more commonly found in the superior nasal quadrant
of the retina. Occasionally, there are small retinal holes next to either of
these entities, with retinal excavations posterior to the meridional folds.
Even though meridional folds do not increase the risk for retinal
detachment, a retinal tear may occur at the posterior edge of a fold in an
eye with a detachment.
40-42


g. Peripheral Pigmentary Degeneration and Pigment Clumping

Peripheral pigmentary degeneration is produced by the proliferation and
migration of retinal pigment epithelial cells into the overlying sensory
retina.
43
The stimulus necessary to produce this condition is probably
inflammation caused by either mechanical disturbances of traction or
biochemical irritation. In some cases, there may be a developmental
component that causes a benign proliferation of pigment epithelial cells
into the overlying retina.
44
Peripheral pigmentary degeneration is usually
visible as a pigmentation that ranges from various sizes of pigment
clumping to a fine, diffuse darkening of the peripheral retina. Isolated
pigment clumps may be located anywhere from the ora serrata region to
many disc diameters posterior to the ora.
45

Peripheral pigmentary degeneration is most common in the superior or
inferior temporal regions of the retina. It tends to be bilateral and is
without gender preference. It has a slight tendency to occur more
frequently in patients under 39 years of age who have WWOP. It is also
associated with a higher frequency of lattice degeneration in patients
over age 40.
45
The literature contains some conflicting statements
regarding the possible association of peripheral pigmentary retinal
degeneration with retinal break formation.
45,46


In extreme cases, peripheral pigmentary degeneration may be confused
with retinitis pigmentosa (RP); however, in RP the pigment is found in
the midperiphery of the retina. RP, which may be accompanied by
attenuated retinal vessels, optic disc pallor, or symptoms of night
blindness, is found in younger patients. Although it is rarely indicated,
electrodiagnostic or visual field testing will help to rule out RP.

12 Retinal Detachment

An isolated pigment clump is a small area of increased pigmentation
(retinal pigment hyperplasia) that occurs due to traction of the overlying
vitreous.
47
These lesions do not have perfectly round, smooth, regular
borders because they are produced by episodes of irregular vitreous
traction. Pigment clumps are small and initially lightly pigmented, but
they become larger and more darkly pigmented over time due to

continued vitreous traction. The clumps probably represent sites of
increased vitreoretinal adhesion. When the traction increases
dramatically, as in a posterior vitreous detachment (PVD) or trauma, the
result may be a retinal tear.
17,42


h. Peripheral Retinal Hemorrhage

The result of bleeding from a retinal artery or vein, a retinal hemorrhage
is caused by either weakness or degeneration of a blood vessel wall (e.g.,
diabetes or hypertension) or by external forces that rupture the vessel
wall (e.g., vitreous traction or traumatic insult). A small, isolated area of
hemorrhage may indicate a retinal tear. Peripheral retinal hemorrhages
appear as round red spots of varying size and number; they form quickly
but may take weeks to slowly resolve.

Peripheral retinal hemorrhages are common among the general
population. Patients with known vascular diseases, systemic
hypertension, diabetes mellitus, and other blood disorders (e.g.,
anemia,
48,49
anticardiolipid antibody disease,
50,51
thrombocytopenia and
other platelet disorders,
52,53
polycythemia,
54
and leukemia

55
) may have
peripheral retinal hemorrhages. Likewise, patients with pulmonary
disease
56,57
or those on anticoagulant drug therapy may have them. Older
persons are more likely than younger ones to develop peripheral
hemorrhages with or without a retinal tear due to the increasing
incidence of PVD.

i. Pars Planitis

Pars planitis, also known as peripheral or intermediate uveitis, is a
chronic inflammation of the peripheral retina and pars plana ciliaris.
Early fundus changes consist of yellowish-gray exudates on the
peripheral retina, ora serrata, and pars plana. These exudates most
Statement of the Problem 13

frequently accumulate in the inferior region of the fundus, presumably
due to gravitational forces. Progression of this condition leads to
coalescence of these exudates into a hazy white plaque over the ora
serrata known as a "snowbank." Fluffy white "snowballs" may float in
the inferior vitreous. There is often peripheral vasculitis, usually
affecting the venules; it is seen as sheathed, attenuated retinal vessels.
Progression of pars planitis can lead to continued obliteration of the
vessels toward the posterior pole, together with the development of optic
atrophy and severe loss of vision. Although the etiology of pars planitis
is unknown, some suggested causes are immune reaction to the patient's
retina or vitreous cells, multiple sclerosis, and cell-mediated immune
disease.

58-62


Pars planitis usually affects children and young adults, seldom occurring
before the age of 5 years or after 30 years of age.
63,64
It can be either
asymptomatic or minimally symptomatic, with such complaints as
asthenopia, floaters, occasional mild ocular redness, and blurred vision.
From 66 to 80 percent of patients demonstrate bilateral involvement.
65-68

Children often do not complain of a slow progressive loss of vision,
especially if it involves the upper visual field; therefore, this disease may
not be discovered until extensive damage has occurred. Nearly one-half
of all patients have serious loss of vision by the time pars planitis is
diagnosed.
67


j. Chorioretinal Scar

The result of an inflammatory process involving the underlying choroid
and retina, usually secondary to infection or trauma, chorioretinal scars
are white to cream-colored fibrotic areas in the fundus and may appear
either excavated or elevated. The margins are often pigmented as a
result of reactive pigment proliferation and migration. These scars,
which can be located in any region of the fundus, are frequently found
close to retinal blood vessels. The overlying vitreous is firmly attached
to the scar because of the inflammatory reaction, and sometimes fairly

dense vitreous bands travel up into the vitreous body, becoming
especially apparent during scleral depression. Significant vitreous
traction on such a scar may result in a retinal tear and subsequent
detachment.
14 Retinal Detachment

k. Posterior Vitreous Detachment

When the vitreous cortex separates from the posterior retina and optic
disc, PVD occurs. Over time, synchysis (liquefaction) and syneresis
(contraction) will cause the vitreous to become more mobile and slowly
shrink. Eventually, the tractional force of the moving vitreous becomes
great enough to begin the separation of the vitreous cortex from the
retinal surface. Although first there may only be a partial or incomplete
separation of the vitreous from a localized region over the posterior
retina, the tractional forces will become great enough to pull the vitreous
from the margin of the optic disc, the area of greatest adherence in the
posterior region. Once the vitreous cortex breaks free from the optic
disc, the anterior separation will continue until it reaches the posterior
margin of the vitreous base.

The forward displacement of the vitreous body results in a retrovitreal
space that fills with liquefied vitreous, mostly through an opening
(prepapillary hole) in the posterior cortex surrounded by the peripapillary
glial ring (known as Weiss's or Gardner's ring) and through small
fractures in the posterior cortex. In addition, aqueous can retroflow from
the ciliary body to aid in filling this space, which can become even larger
than that occupied by the collapsing vitreous body. A large reservoir of
liquefied vitreous and aqueous is available to pass into any retinal break
and assist in the formation of a retinal detachment.

The forward collapsing and rotational motion of the vitreous body on eye
movement can exert substantial tractional forces on isolated areas of
increased vitreoretinal adhesion, possibly resulting in retinal tears.
69, 70

As the vitreous body detaches, the force of the potential motion becomes
greater as separation proceeds. The more vitreous freed from the inner
wall of the eye, the greater its ability to shift with eye movements.
Therefore, in any peripheral areas of increased vitreoretinal adhesion the
collapsed vitreous can have more sudden, strong "whip-like" anterior-
posterior actions.
71, 72
Retinal tears caused by a PVD can be operculated,
horseshoe-shaped, or linear. The symptoms of a PVD are floaters,
photopsia, blurred vision, glare, and rarely, metamorphopsia.

Statement of the Problem 15

Rhegmatogenous retinal detachment is a possible sequela of PVD and is
a natural aftermath of retinal tear formation. One clinical study found
that syneresis and PVD occur in 90 percent of cases of retinal
detachment.
73
Continuous vitreous traction on the flap of a retinal tear
greatly enhances the chances for retinal detachment due to continuous
physical pulling on the sensory retina. The physical traction around a
retinal tear is probably more significant in retinal detachment than the
reservoir of fluid in the retrovitreal space.

B. Epidemiology of Retinal Detachment and Related Peripheral
Vitreoretinal Disease

1. Retinal Detachment

a. Prevalence and Incidence

The incidence of phakic nontraumatic retinal detachment in the general
population is about 1 in 10,000 persons per year (0.01 percent),
74-78
and
the inclusion of traumatic retinal detachment only slightly increases this
percentage. The incidence of retinal breaks in the general population is
about 3.3 percent per year.
6
Therefore, the difference in incidence
between retinal breaks and detachments indicates that the chances of
developing a phakic nontraumatic retinal detachment from most breaks is
fairly low (1:330). Rhegmatogenous retinal detachments are bilateral in
about 15 percent of cases.
79,80


Retinal detachments can occur in persons of any age but are most likely
to occur between the ages of 40 and 70 years
81
(average age for males, 57
years; for females, 62).
77
Only 3-4 percent of retinal detachments occur

in persons under 16 years of age.
82
Retinal detachments, in general, are
more common in males;
81
however, nontraumatic retinal detachments are
more common in females (65.1%) than males (55.7%).
83
Retinal
detachments are also less frequent in African Americans.
81


b. Risk Factors

The most common risk factors for retinal detachments are myopia (40%-
55%), aphakia (30%-40%), and ocular trauma (10%-20%).
81
In patients
16 Retinal Detachment

with aphakia, the incidence of retinal detachment is 1-5 percent; half
occur in the first year following surgery.
84-88
Presumably this is
secondary to PVDs, which frequently occur during this time.
84,85,89-91

Whereas only about 2.9 percent of the adult population have had cataract
surgery, approximately 40 percent of patients with a retinal detachment

have had prior cataract extraction.
73
Cataract patients with extracapsular
cataract extraction (ECCE) and intraocular lens (IOL) implantation have
an incidence of 0 to 2 percent of pseudophakic retinal detachment in the
first postoperative year.
73,87,92-98
However, when posterior capsulotomy
is performed, it essentially negates the advantage of ECCE and the
incidence of detachment increases to 1-3 percent.
99-102
The rate of retinal
detachment increases significantly after surgical loss of vitreous.
103

Furthermore, in patients with pre-existing retinal holes, the increase in
retinal detachment following cataract extraction is substantial.
104


The incidence of the most common type of retinal break in pseudophakic
detachments a flap tear varies from 46 to 90 percent.
105-107
Flap tears
are usually small and located at the posterior margin of the vitreous
base.
108
Retinal tears are of similar type and location, and retinal
detachments have similar morphological characteristics and time of onset
in aphakic and pseudophakic eyes.

84,85,106-110
Aphakic eyes often have
small retinal breaks located close to the vitreous base.

Eyes with lattice retinal degeneration are at risk for retinal detachment,
the incidence of which ranges from 0.3 to 0.5 percent;
14,23
however,
lattice degeneration has been reported to be associated with
approximately 20 to 30 percent of all rhegmatogenous detachments that
have required surgery.
18,29


High myopia (>8 diopters (D) or >24 mm in axial length) is another risk
factor for retinal detachment.
79,111,112
Individuals with high myopia have
a prevalence of retinal detachment of 0.7 to 6 percent.
113-115
One study
showed that for people with myopia over 5 D who live to be 60 years of
age the lifetime risk of developing retinal detachment is 2.4 percent, as
compared with 0.06 percent risk for persons with emmetropia who reach
that age.
116
Patients with over 8 D of myopia have a significant
proportion of retinal detachments but only amount to 1 percent of the
general population.
85

Myopic patients who undergo cataract surgery are
Statement of the Problem 17

especially at risk. However, two separate studies have shown that even
myopic patients with asymptomatic breaks are unlikely to progress to
retinal detachment
89,117
and, therefore, most do not need to be treated
prior to cataract surgery.
118


Trauma significantly increases the risk for retinal detachment because it
can produce a retinal tear or dialysis. Ninety percent of the cases of
severe ocular trauma occur in males who, on average, are 25 years
younger than those with nontraumatic unilateral retinal detachments.
119

In a series of 160 patients, the time between trauma and detachment was
1 month (30%), 8 months (50%), and 2 years (80%).
120,121
Thus, a long
interval after the trauma does not eliminate injury as a potential cause of
detachment.

Glaucoma is also a risk factor, and clinical studies have reported that 4-7
percent of patients with chronic open angle glaucoma developed retinal
detachments.
122-124
This risk is especially evident in patients with

pigmentary dispersion syndrome; retinal detachment has been reported to
occur in 6.4 percent of such cases.
125
Finally, miotic therapy for
glaucoma may be associated with retinal detachment formation. The risk
seems to be greater at the initiation of therapy or with the use of stronger
miotic agents.
103


Patients whose histories include retinal detachment in one eye are at
increased risk for retinal detachment in the fellow eye. The prevalence
in fellow eyes with no predisposing lesions is about 5 percent; in eyes
with predisposing factors, it is 10 percent or greater.
71,74,75,104,126-131

Several studies have shown that when such patients develop retinal tears,
retinal detachments follow in the fellow eyes 25-30 percent of
cases.
127,130,132
Another study found that phakic fellow eyes in patients
who did not receive prophylactic treatment for retinal detachment with
lattice degeneration are 2.5 times as likely to develop retinal detachment
as eyes that receive treatment.
133


Although a number of studies have shown the benefit of prophylactically
treating the fellow eye,
28,134-136

there is a lack of consensus about which
eyes should be treated.
133
When the fellow eye is aphakic, the prevalence
of retinal detachment is reported to be 2-3 times higher (i.e., 21-36
18 Retinal Detachment

percent compared with 10 percent prevalence in phakic eyes).
131,137,138

One study reported that of 100 patients with bilateral surgical aphakia
and a rhegmatogenous retinal detachment in one eye, 26 percent of the
fellow eyes developed a detachment.
139
Therefore, prophylactic
treatment of flap tears in aphakic fellow eyes may be beneficial.
137,140

However, the effect of treating round retinal holes in lattice degeneration
of aphakic fellow eyes is far less clear. Moreover, a family history of
rhegmatogenous retinal detachment places a person at increased risk of
developing a detachment.
20,104,126,129


2. Retinal Breaks

a. Prevalence and Incidence

Retinal tears are found in 1.4 percent of eyes affected with lattice

degeneration.
19
They are most common at the posterior and lateral
margins of lattice lesions. The tears are generally linear in configuration
as they form along the edge of the lesion, but they may progress to a
horseshoe (flap) tear. Occasionally, a giant tear develops along the
posterior margin of extensive lattice degeneration. When such retinal
tears are associated with lattice degeneration, PVDs are usually
responsible for causing a tear along the margin of the lesion. Retinal
tears have a higher incidence of retinal detachment formation; reportedly
about 40 to 75 percent of tractional tears associated with lattice have
progressed to retinal detachment.
23,29,31


The incidence of retinal holes and tears is 12.1 percent in patients with
high myopia.
113
One study of 156 retinal breaks found that 77 percent
were atrophic holes; 13 percent, operculated tears; 10 percent, horseshoe
tears.
141
Lattice degeneration has a reported prevalence of atrophic holes
that varies from 18.2 to 42 percent,
14,19,31
and in one study 75 percent of
all atrophic holes were found in lattice degeneration.
26
Operculated tears
and horseshoe and linear tears are more likely to be found in patients

with PVD, aphakia, pseudophakia, high myopia, or vitreoretinal
degeneration, and in those active in contact sports.

Statement of the Problem 19

Retinal dialyses are uncommon. The post-traumatic type is more
common than the congenital form of dialysis. Males are affected more
frequently than females by both the congenital and post-traumatic forms.

b. Risk Factors

Retinal tears are associated with PVD, aphakia, pseudophakia, high
myopia,
113
vitreoretinal degeneration, and trauma. Syneresis and PVD
are the two most important factors in the development of retinal tears. In
one study of 23 eyes with peripheral breaks, 21 demonstrated more
syneresis than 21 age-matched controls.
142
Most such tears occur
anterior to the equator. The frequency of retinal breaks in eyes with a
PVD has been reported to be between 8 and 15 percent.
142-150
One study
reported finding PVD in 80 percent of eyes with retinal tears.
151


Congenital and hereditary risk factors (e.g., idiopathic weakness of the
peripheral retina and X-linked juvenile retinoschisis) are well known in

the development of retinal dialyses. There are no other known risk
factors for developing a retinal dialysis other than involvement in a sport
or occupation in which head trauma is a frequent occurrence.

Lattice degeneration
14,19,31
and myopia
113
are risk factors for the
development of atrophic holes.

3. Related Peripheral Vitreoretinal Disease

a. Prevalence and Incidence

Retinal tufts. Noncystic retinal tufts are present in about 72 percent of
the adult population. They are bilateral in half of the cases; thus they are
present in 59 percent of adult eyes. Cystic tufts, found in about 5 percent
of the adult population, are bilateral in only 6 percent of the cases; they
are detected in 2.5 percent of adult eyes.
6
Zonular traction tufts, found in
about 15 percent of the population, are bilateral in 15 percent of cases;
thus they are evident in 9 percent of adult eyes.
9


Lattice retinal degeneration. Lattice degeneration is a common finding
in the general population. It has been found in 5-10 percent of autopsied
20 Retinal Detachment

eyes,
15,19,152
and it has a clinical prevalence of 7.1-10 percent.
16,23,31,45,153

The condition, which begins in the second decade of life, is bilateral in
about 50 percent of cases and, therefore, is evident in about 4 percent of
affected eyes.
6,45


Snail-track degeneration. Snail-track lesions have been observed in up
to 80 percent of eyes with lattice degeneration, although the extent varies
considerably.
16


Retinoschisis. The age-related acquired form of retinoschisis is seen in
about 4 percent of the population.
33
It is found more commonly in
persons over 40 years of age and is rare in those under age 20.
24,38,154
It
seems to occur more frequently in females.
155
Advanced retinoschisis,
found in approximately 7 percent of people over age 40,
156

is bilateral
82.1 percent of the time.
154


White-without-pressure. WWOP, found in more than 30 percent of
normal eyes, has a strong tendency for bilaterality. It occurs in only 5
percent of persons over 20 years of age, while in those over age 70 the
frequency of this condition is approximately 66 percent.
157
One study
found a prevalence of zero in myopic eyes with the shortest axial length
and 54 percent in eyes with an axial length over 33 mm.
45


Meridional folds and complexes. Meridional folds occur in about 26
percent of the population and are bilateral in 55 percent of the cases; thus
they are present in 20 percent of all eyes.
6
They are more common in
males. Multiple folds are found in 27 percent of affected eyes.
40

Meridional complexes are found in 16 percent of the population. They
are bilateral in 58 percent of the affected patients; thus are present in 12
percent of all eyes. Meridional complexes are multiple in 45 percent of
affected eyes.
6

Peripheral pigmentary degeneration and pigment clumping.
Peripheral pigmentary degeneration has a prevalence of 6 percent in eyes
of patients less than 19 years of age, 27 percent in eyes in the age group
of 20-39 years, and 41 percent in those over 40 years of age.
45
Myopia is
associated with a higher frequency of this condition.
158
One study found
peripheral pigmentary degeneration had a prevalence of 16.9 percent in
Statement of the Problem 21

myopic patients.
113
Another study found that prevalence varied from
zero in eyes with 21 mm axial length to 75 percent in eyes with axial
lengths in the range of 35 mm.
45
Pigment clumps are commonly found
on routine eye examination; the prevalence rates are probably close to
that of peripheral pigmentary degeneration.

Peripheral retinal hemorrhage. Although peripheral retinal
hemorrhages occur commonly, no specific estimate of their prevalence
has been reported.

Pars planitis. The prevalence of pars planitis was reported to be 7.6
percent and 8 percent for two eye clinic populations,
62,159

although the
rate in the general population would be expected to be much smaller. Of
patients referred for uveitis, 4.3 to 15.4 percent have pars planitis.
62,159-162

The disease is found equally in both genders.
63
The disease seems to
occur more commonly in whites than in African Americans,
62,162
and
there have been reports of familial occurrence of pars planitis.
64,65,163


Chorioretinal scars. Males are more likely than females to have
chorioretinal scars because they have a higher incidence of ocular
trauma.
119
The incidence of postinfective chorioretinal scars is probably
equal for males and females. The incidence of scars is higher in older
patients because they have had a longer period of exposure to trauma and
infection.

Posterior vitreous detachment. In one study of autopsied eyes PVD
was rare in persons younger than 30 years of age, but the prevalence
increased to 10 percent in persons from 30-59 years of age, 27 percent in
persons from 60-69 years of age, and 63 percent in persons over 70.
164

Ultrasonography showed PVD in 75 percent of patients over 80 years of
age.
165
PVD is symmetric in about 90 percent of patients; the fellow eye
usually develops the condition within one or two years.

b. Risk Factors

Lattice retinal degeneration. Lattice degeneration affects both genders
equally, and refractive error does not seem to be an important factor.
18,153

Some have proposed myopia as a factor in the development of this
22 Retinal Detachment

condition. It has been reported to occur in 13.2 percent of eyes with high
myopia.
113
Another study found that the prevalence of lattice
degeneration increased from zero in eyes with short axial lengths of
around 21 mm to 16 percent in eyes with long axial lengths (>36 mm).
45

However, others have reported that its occurrence in patients with high
myopia is nearly the same as for those with low myopia.
166
Although
heredity has been suggested as a factor in lattice degeneration, its role is
unclear.
167

Snail-track degeneration. Snail-track degeneration seems to be
associated with myopia, and heredity may be a risk factor. One study
reported a familial tendency to this condition.
32


Retinoschisis. There are no known risk factors for developing
retinoschisis other than age; however, vitreous degeneration (PVD) is
found in 60 percent of cases of retinoschisis.
38
This relationship may be
coincidental rather than causal.

White-without-pressure. In older persons, WWOP is probably related
to increased vitreous degeneration. In patients of all ages, it occurs most
frequently (22.8%) in myopic patients .
113,168
WWOP has been reported
to occur more frequently in African Americans,
168
but this may be due to
the increased contrast of WWOP against a dark fundus background.

Peripheral pigmentary degeneration and pigment clumping. Lesions
of peripheral pigmentary degeneration can occur in persons of any age,
but they are more likely to be detected in older adults. Persons most at
risk are those with myopia and other conditions causing vitreous
degeneration.

Posterior vitreous detachment. The normal aging process is the usual
mechanism in the development of PVD; however, trauma can also be
responsible for its occurrence. This process may be enhanced by head
trauma; even a slight bump on the head may initiate PVD in older
persons. PVD is more likely to occur in patients with aphakia, myopia,
or vitreoretinal degeneration, and in patients whose history includes
severe ocular trauma or uveitis.

Statement of the Problem 23

C. Clinical Background of Retinal Breaks and Detachment

1. Retinal Breaks

a. Natural History

Atrophic retinal holes are generally stable for long periods. Fluid from
the vitreous can percolate through a hole and produce a small localized
retinal detachment. Such a detachment produces a cuff of whitish
edema. When a pigmented demarcation line occurs at the margin of the
detachment, the lesion has usually been present for at least 3 months and
is relatively stable.
169
This small detachment usually does not require
treatment. Most atrophic retinal holes do not lead to clinically significant
retinal detachment because there is no strong vitreous traction; however,
a retinal hole has a 7 percent chance of progressing to a retinal
detachment.
3

Operculated retinal tears are also stable for a long time. Fluid from
either the vitreous or aqueous can percolate through the break and
produce a small surrounding retinal detachment that may require
treatment. Most operculated retinal tears do not lead to clinically
significant retinal detachments because of release of the vitreous traction
to the involved area during the formation of the operculum. However, in
one study, symptomatic operculated tears without associated subretinal
fluid had a retinal detachment rate of 20 percent; 33 percent of the
asymptomatic operculated tears with associated subretinal fluid
progressed to clinically significant detachment.
104
No reported cases of
asymptomatic operculated tears without associated subretinal fluid
progressed to clinically significant retinal detachments.
30,104,170


Because the vitreous usually remains attached to the apex of the flap and
continues to exert traction (which sometimes can be seen as translucent
vitreous strands, especially upon scleral depression), horseshoe tears are
the leading cause of rhegmatogenous retinal detachments. Symptomatic
horseshoe tears have a 30-55 percent chance of progressing to retinal
detachment,
19,104,134
and even asymptomatic flap tears with associated
subretinal fluid (localized detachment) have a 40 percent chance of
progressing to retinal detachment. However, in the absence of subretinal
24 Retinal Detachment

fluid in asymptomatic flap tears, only 10 percent progressed to retinal
detachment.
104
The frequency of these tears increases with age,
suggesting a degenerative nature. Lateral tears may develop at the bases
of large flap tears due to continued traction on the flap. With time, the
lateral tears may enlarge into giant tears; such tears and the associated
detachments are then more difficult to repair.

Vitreous hemorrhage, which is frequently concomitant with retinal tears,
is the result of the rupture of a retinal vessel during the tearing process.
The proximity of a retinal vessel that bridges the break (from the flap to
the surrounding retina) may enhance the chances of bleeding into the
vitreous due to its continued traction on the vessel.

Retinal dialysis often produces asymptomatic and slowly progressive
retinal detachment, characterized by successive demarcation lines. When
a detachment is stable in one location for more than 4-6 months, the
traction of the detached retina on the attached retina can stimulate
reactive hyperplasia of the underlying pigment epithelium. The result is
the appearance of a "tidewater" pigment line. A retinal detachment
associated with a post-traumatic dialysis may be deceptive in that it often
occurs weeks to months following the traumatic event. The tearing
process can result in a shearing of retinal vessels that causes a
hemorrhage into the vitreous. The retinal dialysis may not be visible
initially due to vitreous hemorrhage or retinal edema. Sometimes the
trauma induces chorioretinal inflammation at the site of the dialysis,
producing a scar and preventing retinal detachment. The posterior edge
of a dialysis tends not to form the roll commonly seen in giant retinal

tears. The clinician should suspect a retinal dialysis if the retinal
detachment extends onto the pars plana. The risk for a retinal
detachment from a retinal dialysis is reported to be approximately 20
percent.
18,171


b. Common Signs, Symptoms, and Complications

Pigment cells floating in the anterior region of the vitreous cavity, which
can be found during biomicroscopic examination, may be a sign of a
retinal tear.
172
Known as "tobacco dust" or Shafer's sign, these cells are
the result of pigment epithelium exposure to vitreous fluid. The pigment
Statement of the Problem 25

epithelial cells may dislodge from the RPE and float off into the fluid
spaces beneath the detachment or into the vitreous cavity; however, the
lack of cells at examination cannot be used as a definite indication that a
tear is not present.

Hemorrhage may also have occurred in the vitreous. Vitreous
hemorrhage with PVD increases the chance that a retinal tear will occur;
about 15 percent of patients with PVD have retinal tears. With vitreous
hemorrhage the incidence of tears increases to as high as 70 percent, as
opposed to a 2-4 percent incidence of the tears without hemorrhage.
173

The sudden onset of numerous floaters and the occurrence of flashes of
light are hallmarks of a potential retinal tear. Significant vitreous
traction on the retina can result in the perception of a flash of light
(photopsia), and because retinal tearing usually requires significant
physical traction, photopsia is a common finding in the early stages of
retinal tear formation. The sudden onset of numerous floaters with a
retinal tear is the result of bleeding into the vitreous. The bleeding is
produced by the shearing of a retinal blood vessel during the formation
of the tear. The red corpuscles floating in the fluid reservoir of the
vitreous are very small, and only those adjacent to the retinal surface will
cast a shadow significant enough to be detected as black specks moving
across the visual field. Inasmuch as most retinal tears are found in the
peripheral retina, the floaters usually appear in the periphery of the visual
field and move across the central field in a matter of hours.

The complications of a retinal tear are vitreous hemorrhage and retinal
detachment. Vitreous hemorrhages are generally small, transient, and
resolve without significant sequelae. Larger hemorrhages can cause
blurry vision that may take weeks to clear.

2. Retinal Detachment

a. Natural History

The vitreous traction usually responsible for producing a tear in the
retina creates a portal through which fluid in the vitreous cavity can gain
access into the potential space between the sensory retina and the
26 Retinal Detachment

underlying pigment epithelium. Continuous traction is influential in

physically separating the sensory retina from the RPE. When these two
forces are strong enough, either alone or in concert, a retinal detachment
can begin or an established retinal detachment can progress.

Approximately 30-50 percent of rhegmatogenous retinal detachments are
caused by retinal tears demonstrating vitreous traction; only 10 percent
result from asymptomatic retinal breaks.
18,104,171
Most retinal
detachments occur in the far periphery of the retina, then advance toward
the posterior pole and the macula. Because of its peripheral location, a
small, early detachment is usually asymptomatic (i.e., the person often is
unaware of the loss of an area of peripheral vision).

A nonrhegmatogenous retinal detachment is similar to a rhegmatogenous
detachment but lacks a retinal break. Whereas the fluid under a
nonrhegmatogenous detachment is rich in proteins, it is more viscous
than the fluid found beneath a rhegmatogenous detachment; therefore, it
tends to shift with head movement and rarely extends to the ora serrata.
The absence of a break upon a retinal detachment should alert the
clinician to the possibility that the eye harbors a choroidal tumor, which
may be difficult to detect under the retinal detachment. The most
common tumors metastatic to the choroid are lung and breast
carcinomas.
174
About 75 percent of choroidal malignant melanomas
have secondary retinal detachments.
175

b. Common Signs, Symptoms, and Complications

Early symptoms of retinal detachment (photopsia and/or a sudden
shower of floaters due to tearing of a retinal blood vessel) are often the
result of vitreous traction. Left unchecked, most clinically significant
retinal detachments will eventually enlarge and probably advance toward
the macula. As the detachment becomes larger and the resultant visual
field defect encroaches on the center of vision, the person will notice
what appears to be a "shadow" or "curtain" moving in over his or her
vision. When the macula detaches, the person experiences a significant
loss of central vision. Because the retina has no pain receptors, neither
the tearing nor the physical detachment of the retina is accompanied by
pain.
Statement of the Problem 27

A retinal detachment of recent onset will undulate easily during eye
movements. A longstanding detachment does not undulate because of the
scarring and contraction of the degenerative sensory retina that occur over
time. The further into the vitreous cavity the retina floats, the more elevated
it appears during ophthalmoscopy and the greater the number and size of
retinal folds in the detachment. In longstanding detachments, the scarring
and contraction of the degenerating retina cause the folds to flatten and even
disappear with time. A recent detachment appears whitish due to the edema
of the outer retinal layers when the sensory retina is separated from its outer
blood supply, the choriocapillaris. Longstanding detachments, having
undergone degenerative processes, have many characteristics similar to
those of retinoschisis (e.g., retinal thinning and a transparent appearance).

3. Early Detection and Prevention

Early detection and treatment of a retinal tear may help to prevent the
formation of a retinal detachment or the expansion of a pre-existing
detachment. Patients at risk should be informed about the symptoms of a
retinal tear and retinal detachment (e.g., floaters, flashes, curtain, or shadow)
and told to seek care immediately if these symptoms develop. Periodic
dilated fundus examinations should be conducted to monitor the status of the
retina.

When a retinal detachment is small and located in the periphery of the retina,
early detection and treatment can help reduce the risk of vision loss
associated with larger or more central detachments. A detachment that is
detected early will more likely require less extensive surgery, which is more
likely to result in successful reattachment. The most important reason for
early detection is to prevent involvement of the posterior pole and
detachment of the macula. If the peripheral retina in a symptomatic patient
cannot be evaluated adequately, referral to a more experienced examiner is
appropriate.
103
Failure to detect a retinal detachment is likely to allow the
detachment to become more extensive, increasing the chance of involving
the macula. Nearly every eye with a symptomatic retinal detachment will
become blind unless the detachment is surgically repaired.
The Care Process 29

II. CARE PROCESS

This Guideline describes the optometric care provided to a patient with a
retinal detachment or related peripheral vitreoretinal disease. The
components of patient care described are not intended to be all inclusive.
Professional judgment and individual patient symptoms and findings

may have significant impact on the nature, extent, and course of the
services provided. Some components of care may be delegated.

A. Diagnosis of Retinal Detachment and Related Peripheral
Vitreoretinal Disease

Evaluation of patients with retinal detachment or related peripheral
vitreoretinal disease includes the elements of a comprehensive eye and
vision examination.*
*
It may include, but is not limited to, the following
areas:

1. Patient History

The clinician should review the patient's present and past history of
ocular and systemic disease and elicit information regarding:

• Loss of vision
• Sudden, recent onset of floaters
• Flashing lights
• Loss of peripheral visual field
• Family members with loss of vision or history of retinal disease
• History of trauma.

2. Ocular Examination

The examination for retinal detachment and related peripheral
vitreoretinal disease may include, but is not limited to:

*
Refer to the Optometric Clinical Practice Guideline for Comprehensive Adult Eye and
Vision Examination.
30 Retinal Detachment

• Best corrected visual acuity
• Pupillary responses
• Biomicroscopy
• Binocular indirect ophthalmoscopy, with scleral indentation if
indicated
• Tonometry
• Visual field screening (confrontation)
• Retinal drawing or photodocumentation, if indicated.

3. Supplemental Testing

The interpretation of data obtained during the examination may indicate
the need for additional testing which may include, but is not limited to:

• Fundus biomicroscopy with Hruby lens, fundus contact lens, or
other precorneal condensing lens
• Ultrasonography
• Fluorescein angiography
• Formal visual field testing.

Binocular indirect ophthalmoscopy with pupillary dilation is generally
necessary for diagnosis of a peripheral retinal break or detachment.
During ophthalmoscopy, the underlying choroidal detail is obscured by
the detached retina, a helpful sign in detecting the presence of a retinal

detachment. Scleral depression may be needed to detect small,
asymptomatic peripheral retinal detachments. The biomicroscope can be
used to search for breaks in detachments using a mirrored fundus contact
lens, a hand-held precorneal fundus lens, or a wide-field fundus contact
lens. A search for all possible retinal breaks should be performed, and
any breaks discovered should be accurately drawn on the patient's chart
or photodocumented.

The biomicroscopic examination can also be useful in detecting a
rhegmatogenous retinal detachment or a retinal tear without a significant
associated detachment by the observation of pigment cells floating in the
anterior vitreous cavity immediately behind the lens (Shafer's sign or
"tobacco dust").
172
These pigment cells can migrate from the uncovered
The Care Process 31

pigment epithelium, float through the retinal tear in the detachment, and
spread into the vitreous cavity; however, the absence of these cells is no
guarantee that a retinal tear is not present.

An afferent pupillary defect is common in the eye with a clinically
significant retinal detachment, but it is not likely to occur in an eye with
a small peripheral detachment. The practitioner should be alert to the
possibility of a detached retina when there is a reduction in central visual
acuity, which will occur if the detachment involves the macular area.

Sometimes a visual field screening test can aid in the detection of a
visual field loss from a clinically significant retinal detachment before
pupillary dilation and ophthalmoscopy. However, visual fields are

usually ineffective in evaluating patients because measurable field loss
occurs only in advanced cases.

Ultrasonography can be used to detect a retinal detachment, especially
when the view of the fundus is poor or impossible due to opacification of
the ocular media (e.g., dense corneal scars, cataracts, dense pupillary
membranes, or dense vitreous scarring or hemorrhage). Ultrasonography
can be used to differentiate a retinoschisis from a retinal detachment; a
recent retinal detachment is thicker than a retinoschisis and shows a
greater sound echo on the monitor screen. Ultrasonography can also help
discover a subretinal tumor that may be causing a nonrhegmatogenous
retinal detachment.

B. Management of Retinal Breaks and Detachment

The extent to which an optometrist can provide treatment for retinal
breaks or detachments may vary depending on the state's scope of
practice laws and regulations and the individual optometrist's
certification. Management of the patient with retinal breaks or
detachments may require consultation with or referral to a retina
specialist, if available, or to a general ophthalmologist who has
experience in retinal disease, for those services outside the optometrist's
scope of practice.
32 Retinal Detachment

1. Management Strategy for Retinal Breaks

The optometric management of the patient with peripheral vitreoretinal
disease is summarized in Appendix Figure 1. The management strategy
varies with the type and severity of the retinal break.

Most asymptomatic tears have a low propensity to progress to retinal
detachment and, therefore, can generally be followed without treatment,
especially in the absence of vitreous traction in the involved
area.
30,36,117,176
However, an asymptomatic tear in the at-risk patient with
aphakia, pseudophakia with posterior capsule rupture, high myopia, or
vitreoretinal degeneration, or in the patient who is active in a contact
sport, or one who has a personal or family history of retinal detachment
should be referred to a retina specialist or general ophthalmologist
experienced in retinal diseases for consideration of retinopexy.

The patient with a symptomatic PVD should be followed at least every 2
to 3 weeks until the condition becomes asymptomatic and no retinal tears
can be found. The patient should be advised to return immediately if
there is a sudden onset of tiny black specks, if photopsia occurs or
increases, or if a curtain appears in his or her visual field, either during
the acute phase or at any time later.

Most atrophic retinal holes do not require treatment because they are not
associated with vitreous traction.
30,36,117,176
Some studies have shown that
atrophic holes in aphakic eyes can be safely followed without
treatment.
117,177
Asymptomatic operculated tears (those not associated
with vitreous traction) are very unlikely to progress to retinal detachment
and generally do not require treatment.

103
However, upon discovery of
atrophic retinal holes or asymptomatic operculated tears in patients at
risk (e.g., aphakia, pseudophakia, high myopia, or vitreoretinal
degeneration, as well as those who are active in contact sports, or who
have personal or family histories of retinal detachment), a consultation
with an ophthalmologist for possible treatment may be needed.

Autopsy and clinical studies have shown at least one retinal break in
approximately 5-15 percent of the general population, but most of the
subjects had never developed a retinal detachment.
11,23,24,26,85,148,176,178

The Care Process 33

Even though a retinal break is essential in the production of a
rhegmatogenous detachment, only about 1 in 70 eyes with a retinal break
will develop a retinal detachment.
30,178,179
Peripheral atrophic retinal
holes and operculated retinal tears should be drawn on the patient's chart
or photodocumented, if observable with the fundus camera, for future
reference.

The patient with a symptomatic operculated tear, especially if it involves
subretinal fluid (i.e., localized detachment), should also be referred to an
ophthalmologist for possible retinopexy. Fresh, operculated tears, which
are large and superiorly located or associated with significant vitreous
hemorrhage, should also be considered for treatment.
103

Although simply following asymptomatic flap tears may be sufficient,
treatment of the tears is common because of concern that retinal
detachment may occur. Flap tears in aphakic or pseudophakic patients
should be treated, especially if the tears are large or located
posteriorly.
89,117,177
Patients with symptomatic tears, with or without
subretinal fluid (localized detachment), should be referred immediately
for retinopexy.

Due to increased risk for vitreous hemorrhage from a bridging blood
vessel in a retinal tear, some retina specialists believe it necessary to treat
the eye with photocoagulation or scleral buckling.
180
Others believe that
a bridging blood vessel will hemorrhage, with or without treatment.
181,182


The patient with a retinal dialysis tear should be referred to a retina
specialist or general ophthalmologist experienced in retinal disease.
Such a condition usually requires treatment due to its propensity to
produce a retinal detachment. Treatment consists of retinal detachment
surgery with scleral buckling and cryotherapy or expanding gas
injections into the vitreous cavity. A retinal dialysis tear should be
drawn on the patient's chart, or photodocumented if the retinal dialysis is
observable with the fundus camera, for future reference if the patient
declines treatment.

It is important to involve the patient in the treatment decision making
process; it reduces anxiety and makes the patient more relaxed and
34 Retinal Detachment

cooperative.
81
The optometrist should tell the patient that the risk
associated with the treatment of a problematic retinal tear is less than the
risk of developing a retinal detachment. Prophylactic treatment of a
symptomatic retinal tear decreases the likelihood of subsequent retinal
detachment to approximately 5 percent (studies vary from 1.4%-
7.8%).
28,134,135,169,183-186


The most common complications of peripheral retinopexy are formation
of a macular pucker, which occurs in about 3 percent of cases (range,
0%-2.2%),
20,170,187
and formation of additional retinal tears due to
vitreous shrinkage in about 5 percent of cases (range, 2.1%-6.7%).
20,187

The probability of developing a retinal detachment following treatment
varies from 1.8 to 6.2 percent.
20
The most frequent cause of a retinal
detachment subsequent to prophylactic retinopexy is inadequate
treatment of the retina anterior to the flap tear.

170,188,189


2. Management Strategy for Retinal Detachment

The optometric management of the patient with retinal detachment is
outlined in Appendix Figure 2.

Initial management of the patient with retinal detachment includes
restriction of physical activity and reduction in eye movement. In some
cases, bilateral patching can reduce the potential effect of inertial forces
caused by head and eye movements that could increase the size of the
detached area.

Without surgery, nearly every eye with a symptomatic retinal detachment
will become blind. Following the diagnosis of significant retinal
detachment, the optometrist should make an immediate referral to a
retina specialist for surgery. Even subclinical retinal detachments around
breaks (e.g., detachments caused by subretinal fluid that extends at least
1 DD from the break, but no more than 2 DD posterior to the equator)
may require treatment since as many as 30 percent of them will progress
to clinically significant detachments.
104
However, some longstanding
subclinical detachments may simply be followed.
103
Spontaneous
reattachment of a retinal detachment rarely occurs. The success rate of
The Care Process 35

surgical reattachment is high, although more than one procedure may be
needed.
20,190-192


Treatment for retinal detachment consists of creating an effective
chorioretinal adhesion to prevent leakage of fluid between the sensory
retina and the underlying pigment epithelium. Laser photocoagulation or
cryotherapy can be used to create a scar that attaches the surrounding
retina to the underlying choroid to prevent a subsequent retinal
detachment. A scleral buckle results in close apposition of the retinal
tear to the retinopexy treated area and has the added effect of reducing
transvitreal traction. Some alternative treatments are pneumatic
retinopexy, expanding gases, air injection, silicone oil injections, and
vitrectomy, all of which have advocates and have been shown to be
effective in certain situations. Whenever the macula is threatened by the
advancing detachment, it should be treated as soon as possible to prevent
loss of central vision.
192-195


There is no evidence that lattice degeneration without holes requires
treatment, and prophylactic therapy is of little value.
31,103,196
However, a
recent study showed that prophylactic treatment of lattice degeneration in
the phakic fellow eye of patients with retinal detachment reduced the
chances of subsequent detachment from 5.1 to 1.8 percent over 7
years.
196

When retinal tears are found with this condition, it is prudent to
refer the patient to a retina specialist or a general ophthalmologist
experienced in retinal disease for consideration of appropriate treatment
modalities.

Because retinal detachment associated with a retinoschisis is uncommon-
-and even if a detachment does occur, the progression is very slow most
retinoschises with outer layer breaks need not be treated.
103
Treatment
may be considered if the retinoschisis has large, multiple, or posterior
breaks, or if breaks in a retinoschisis coincide with a retinoschisis
detachment in the fellow eye.
36
However, some clinicians believe that
treatment is indicated only if the retinoschisis is associated with
progressive, symptomatic retinal detachment.
37
A patient who has
retinoschisis with holes in both the inner and outer layers should be
referred to a retina specialist for possible treatment. Such treatment
consists of cryopexy or laserpexy, which is successful in completely
36 Retinal Detachment

flattening the lesion in about 50 percent of the cases.
197
When the
retinoschisis is advancing toward the macula, the patient should be
referred to a retina specialist or a general ophthalmologist experienced in
retinal disease for possible prophylactic laser treatment just posterior to

the leading margin of the lesion.

3. Patient Education

The optometrist should educate the patient about the symptoms of a
retinal detachment, retinal tear, or related peripheral vitreoretinal disease
and advise him or her to return immediately if the symptoms occur.
Prompt recognition of symptoms will increase the chances for successful
surgery and better postoperative visual acuity.
102,195
Studies have
confirmed that the success rate for retinal detachment repair in the fellow
eye of a previous retinal detachment is higher and that the visual acuity
results are better with early detection.
131,137


4. Prognosis and Followup

The prognosis for the patient with a retinal break and the need for
followup by the optometrist depend on the type and severity of the break.
The frequency and composition of evaluation and management visits and
the prognosis for patients with specific conditions are summarized in
Appendix Figure 3.

a. Retinal Breaks

The prognosis for patients with atrophic holes is good due to the low
propensity to progress to retinal detachment. Patients with atrophic
retinal holes should have yearly eye examinations, but those with

surrounding localized (<1 DD) retinal detachments should be seen every
6 to 12 months.

The prognosis for patients with operculated tears is good because the
propensity to develop a retinal detachment is fairly low. Patients with
asymptomatic operculated retinal tears should have yearly eye
examinations, and patients with symptomatic tears, who decline referral
or treatment, should be seen every 3 to 6 months.
The Care Process 37

The prognosis for patients with horseshoe or linear tears is guarded
because of the high probability that the tears will progress to retinal
detachment. Following prophylactic treatment, most clinicians see the
patient in 1 week and again in 3 to 6 weeks. Even for patients who are
successfully treated, followup examinations are essential.
103
In one
study, 7 percent of such patients developed additional breaks, and 95
percent of the breaks occurred in the first 3 months following
treatment.
198
Patients with untreated asymptomatic horseshoe or linear
retinal tears who decline referral for treatment should have eye
examinations every 6 months.

The prognosis for the patient with a retinal dialysis tear is poor because
there is a high propensity for progression to retinal detachment.
However, the prognosis is generally favorable following surgical
treatment.

b. Retinal Detachment

The prognosis for recovery is poor for the involved area of a detached
retina due to degeneration of the detached photoreceptors over time. In
general, the longer the retina is detached, the greater the possible loss of
vision after reattachment of the retina. The prognosis is very poor when
the detachment involves the macula. The longer the macula is detached,
the poorer the resultant central visual acuity. A postoperative visual
acuity of 20/20 is sometimes achievable following reattachment of the
macula, but it is rare. Therefore, when a detached macula is reattached
within a few days, there is a chance of retaining the pre-existing visual
acuity. Even when 20/20 vision is achieved, the patient may experience
and complain of metamorphopsia (distorted vision).

A number of complications following scleral buckling procedures have
been reported. They include anterior segment ischemia syndrome,
corneal damage, ptosis, lagophthalmos, heterotropia, symblepharon,
trichiasis, entropion, ectropion, implantation cyst, glaucoma, cataract,
delayed intraocular hemorrhage, cystoid macular edema, central retinal
artery occlusion, optic atrophy, sympathetic ophthalmia, phthisis bulbi,
and proliferative vitreoretinopathy (PVR).
199
Macular pucker occurs in 3
to 8.5 percent of patients with rhegmatogenous retinal detachments who
38 Retinal Detachment

receive photocoagulation or cryopexy during the detachment
surgery.
170,187,200
Patients having tears with rolled edges, equatorial

ridges, and contraction scars on the detached retina are more likely to
develop a macular pucker after a scleral buckling procedure.
201


The patient's initial followup visits after retinal detachment surgery are
usually performed by the retina specialist. Subsequently, the patient
should be evaluated by the referring optometrist within a year of the
surgery and yearly thereafter for dilated retinal examination to ascertain
the status of the retina and to detect subsequent retinal tears on the
buckle or other retinal areas.

5. Management of Patients with Severe, Irreversible Vision Loss

The patient who has a retinal detachment with macular involvement or
related peripheral retinal disease with macular sequela may suffer
permanent central vision loss. Consultation with an optometrist who has
advanced training or clinical experience in low vision is advisable.
Patients may benefit from low vision rehabilitation that includes the use
of specialized optical devices and training.

Patients should be evaluated to determine their potential to benefit from
comprehensive low vision rehabilitation that reduces the debilitating
effects of vision loss from a previous retinal detachment. This task-
oriented evaluation may include, but is not limited to:

• Expanded patient history and needs assessment
• Low vision assessment of visual acuity (including eccentric
viewing)
• Low vision refraction

• Binocular function assessment
• Supplemental testing, including visual fields, contrast sensitivity,
and color vision
• Response to optical and electro-optical magnification
• Response to selective absorption filters.

Once appropriate optical requirements have been determined, the
clinician should educate and train the patient in methods of improving
The Care Process 39

visual function with and without optical devices. The patient should be
encouraged to use prescription optical devices for work, home, and social
activities.

The goal of low vision rehabilitation is to reduce ocular morbidity and
enhance the quality of life. In addition to optical intervention, the
evaluation should include the need for nonoptical devices, special
lighting, posture aids, contrast enhancement, enlarged print, and
nonvisual methods or devices when appropriate. These devices, which
significantly enhance the rehabilitative process, are necessary to
complement the use of optical devices.

When indicated, the optometrist should recommend blind rehabilitation,
occupational, vocational and independent living counseling services, and
psychosocial consultation. Patients should be informed of other
resources including agencies that register and provide services and
advocacy to individuals with legal blindness or visual impairment.
These agencies can provide information regarding large-print and talking
books, independent travel aids, and other devices geared to improve the
patient's quality of life and ability to function in their own households.

The optometrist should provide the patient written documentation of his
or her status relating to legal blindness for state and federal (Internal
Revenue Service) tax requirements. Local and national support groups
for the visually impaired assist many patients in coping with the anxiety
and concerns of vision loss. Such groups also provide information
regarding resources to help patients function safely and productively in
their environment.

Conclusion 41

CONCLUSION

The optometrist is in a position to diagnose peripheral retinal conditions
that are of great significance to the ocular health of his or her patients.
Through early detection and timely treatment, preventive measures can
protect and maintain the patient's ocular health and vision. A
comprehensive eye examination, including a stereoscopic retinal
examination through a dilated pupil, enables the optometrist to diagnose
potentially sight-threatening conditions. Management of the patient with
peripheral retinal disease involves appropriate documentation, patient
followup, and, when appropriate, referral for consultation with or
treatment by a retina specialist or a general ophthalmologist experienced
in retinal disease.

42 Retinal Detachment

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